Devices for tautening the cover of folding boats



H. HART 1,822,810 a DEVICE FOR TAUTENING THE COVER OF FOLDING BOATS Sam, 8, 193?.

Filed July 15, 1950 Patented Sept. 8, 1931 HANS HART, F MUNICH, GERMANY DEVICES roe V'IAUTENING THE COVER. or FOLDING soars Application filed July 15, 1930, ser'nu No. 468,037, and in Germany May a, 1930.

I have filed applications in Germany on May 3, 19 30 Switzerland, May 16, 1930 Austria, lVIay 1-5, 1930.

he tautening or stretching of the cover of folding boats is a matter of considerable difliculty, since both the cover and the boat frame are'liable to change their shape in consequence of the necessary elasticity of the materials used in their manufacture; this change of shape can result in a very detrimental play or free motion between the two most important components of the boat, namely, cover and frame. .The attempt has been made to eliminate this play in different ways, for instance, by employing adjustable stays or struts at the front and rear end of the frame to press the longitudinal rods against the cover. These tautening devices are, however, of little practical value, in consequence of the trouble entailed by their assembly, also because said struts or stays obstruct the interior of the boat, and finally, because the tautening of the cover is irregular and the points of application of the pressure are frequently strained excessively, this again resulting in the formation of creases.

The present invention relates to a tautening device for the cover of folding boats which entirely eliminates the above disadvantages: in the first place, the stretching or tautening of the cover entails no separate or individual manipulation, but is on the contrary entirely automatic; and secondly, the tautening action can be applied to any desired part of the cover. In this Way the formation of creases, both local and of greater extent, is effectually and permanently prevented. m The device according to the present invention provides automatic tautening means arranged at or in suitable units of the frame, which means permit the movement of the individual frame units outwards and result in a permanent tautening of the cover when the frame has been assembled.

The possible forms of execution of the device according to the present invention are various; in the accompanying drawings three examples of a boat frame provided with the in a longitudinal direction;

tautening device according to the present in vention are shown diagrammatically.

Fig. 1 shows a folding boat frame in plan view and Fig. 2 the same'i-n side View, in which the longitudinal frame rods consist of individual units a, which are connected by means of sleeves Z); when assembling the boat, the parts a are firmly pressed into the sleeves b and the tautening of the frame is then attained in known manner by means of a jointed lever arrangement of the boat floor or the side or borders.

igs. 3 and l disclose modifications of the device. I

According to the present invention the units a are automatically pressed by elastic means c, which may consist of spiral metal springs, rubber or other suitable material. The action of the elastic means 0 can be imparted to the units a in various ways; in Figs. 79 1 and 2 this is attained by inserting the spiral springs 'c in the sleeves b, which, as explained above, serve to connect the individual units a. The length and power of the spiral springs is such that they are pressed together when the frame is stretched, thus pressing the latter tightly against the cover. The tautening of the cover takes place over its entire are-a,since the springs c are arranged in 7 all longitudinal frame rods. According to the manner of j unction of the latter with the ribs 49, this tautening can be limited to the longitudinal direction, or it can be caused to take effect in two directions, namely, in the longitudinal and-at right angles to the longi- 'tudinal. If the units a are rigidly attached to the ribs 8, only the sten'i and stern of the boat will be effective in stretching the cover (the cover is not shown in the drawings). If, on the other hand, the units a are movably attached to the ribs 8-, for instance, by means of a sliding or groove joint, the springs 0 will, in consequence of the curved form of the longitudinal rods, also be effective in the direction of the m ribs. Whether the longitudinal tautening or a tautening in the direction of the ribs or'a combination of both is employed depends solely on the design of the frame. According to the length of the individual units a cover, said frame comprising a plurality of and position of the sleeves Z) the spring pressure can at will be limited more or less to the stem and stern, or to the central portions of the frame, or again, be uniformly distributed over all units of the boat frame; in this way the tautening effect can be varied to suit each individual type of boat. Also, the springs 0 can at any time be exchanged for longer or shorter ones; or again, these springs may be arranged not only between the individual units a, but also outside the latter, andthe action of these springs may be either direct or indirect. The tautening action is entirely automatic and takes place as soon as the frame is inserted in the cover.

If a tautening effect in only one direction is desired, the forms of construction shown in Figs. 3 and I may be employed; according to Fig. 3, the tauteningefl'ect is only in the longitudinal direction and in Fig. 4 only in the direction of the boat ribs. In Fig. 3 the stem proper 7c is provided with an auxiliary stem pressed outwards by springs 0; sliding connection between the auxiliary stem 70 and the stem proper 7c is attained by. pins attached to 76 moving in holes of the stem 70 these pins can with advantage be used as guides for the tautening springs c. This tautening device can be arranged either at the bow or stern of the boat or at both bow and stern; in the case of small folding boats this form of construction is generally suflicient to effect the necessary tautening of the cover when the frame is inserted in the latter. The form of construction according to Fig. 4 is chosen when it is desired to exert the tautening pressure also in the direction of the ribs, or in this direction alone. In this case the rib s is provided at its outer ends with auxiliary rib end pieces 8 which are spring pressed by springs 0 in an outward direction as described above for Fig. 3. Similar auxiliary pieces 8 shown in the drawing by dotted lines, may-also be provided for the deck stays in order to tauten the spray deck. Whether all ribs or only a certain number are provided with such tautening devices will depend on the size and kind of the boat cover. The springs 0 may also be arranged for tensile strain instead of pressure, for instance, by placing them on the inside of the stems or ribs. It remains for the designer in each individual case to decide which of the many possible forms of construction or combinations of these should be employed.

What I claim as my invention, is:

1. A boat comprising an extensible frame, a flexible cover, resilient elements interposed between the members of the frame on opposite sides of the boat,said resilient members being disposed to exert forces in both longitudinal and transverse directions to impart a tautening effect on said flexible cover.

2. A boat comprising a frame, a flexible longitudinally arranged extensible members, springs interposed between said members in the longitudinal direction thereof to cause said frame to impart a tautening effect on said flexible cover.

3. A boat comprising a frame, a flexible cover, said frame comprising a plurality of longitudinally arranged extensible members, sleeves receiving the ends of said members. and resilient elements arranged in said sleeves and interposed between the ends of the extensible members to cause said frame to exert a tautening effect on said flexible cover.

4. A boat comprising an extensible frame, a flexible cover, said frame comprising an intermediate frame and relatively extensible end frames, and resilient elements interposed between said frames to exert a force tending to separate said frames and impart a tauten ing effect on said flexible cover. 7

5. A boat comprising an extensible frame, a flexible cover, and resilient elements interposed between members of the frame on opposite sides of the boat to impart a tautening eifect on said flexible cover.

In testimony whereof I affix my. signature.

HANS HART. 

